A positive response is seen with flexion of the terminal phalanx of the thumb.
2.
The test involves tapping the nail or flicking the terminal phalanx of the middle or ring finger.
3.
The terminal phalanx, with the claw attached, folds back in the forefoot into a sheath by the outer side of the middle phalanx of the digit, and is retained in this position when at rest by a strong elastic ligament.